However, Searle said registering was too expensive for small suppliers who only had a few cows. As a result, an underground market was growing in the region.

"It's word of mouth. It's clearly not advertised."

For Searle, this was more a return to traditional ways than a fad.

An uncertified supplier, who asked not to be named, said supplying raw milk without certification was a kind of "underground resistance" to government regulations and big milk producers.

"If you keep it underground then you can do it and keep going but if you advertise it then you have to conform to all the specifications.

"Just because the Government says it's wrong, doesn't mean we're not going do it."

Christchurch resident Jackie Donn has been buying raw milk for two years from "a private supply of milk which is quite legitimate".

"I like the raw milk because it has far more goodness in it," she said.

A raw milk drinker who asked not be named said her migraines, hay fever, and allergy to mosquito bites receded since she switched from pasteurised milk three years ago. Her son's eczema had improved too.

The woman said she trusted her supplier despite them possibly not being certified.